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The increasing demand for soilless media, sustainability issues with peatmoss, and increasing cost of peatmoss have prompted studies of more environmentally friendly and less expensive substitutes. Biochar, a lightweight black carbon material produced by the pyrolysis of biomass, has gained popularity as a soilless media supplement. The objective of this study was to evaluate Eastern red cedar (ERC) biochar as a supplement to soilless media for the production of chrysanthemum and ornamental kale. Treatments included ERC biochar produced at three different temperature ranges of 300 to 350 °C, 400 to 450 °C, and 500 to 550 °C that were applied at 25%, 50%, and 75% v/v plus a control (100% v/v of standard commercial mix). Additionally, ERC bark was applied at the same rate as biochar. The 300 to 350 °C and 400 to 450 °C temperature ranges increased the bulk density of the media, whereas total porosity was greatest with just bark. Regarding the physical properties of the media, in general, the 75% v/v supplementation rate of ERC bark or biochar at any temperature increased air porosity but decreased the water holding capacity, except for the water holding capacity at 500 to 550 °C. As the biochar production temperature increased, so did the pH and electrical conductivity (EC), whereas volatile matter decreased. Plant height, width, shoot dry weight, root dry weight, number of flowers (chrysanthemum only), flower diameter, and water use efficiency were greatest with the 100% v/v soilless media for both species. In general, chrysanthemum plants grown with 25% v/v biochar supplementation or bark had similar height, width, and shoot dry weight at any temperature compared with those grown with the 100% v/v soilless media. For ornamental kale, the 25% v/v 400 to 450 °C biochar supplementation showed plant height and water use efficiency similar to those of the 100% v/v soilless media. In general, 25% ERC bark performed similar to 25% v/v and 50% v/v biochar at any temperature for plant width, shoot dry weight, root dry weight, water use efficiency, and root-to-shoot ratio. The media nutrient content and EC were greater with 100% v/v soilless media and a lower rate (25% v/v) of ERC bark and biochar than with higher rates. The higher levels of biochar were harmful and reduced the ornamental kale growth and quality. These results suggest that supplemented soilless media with lower rates (25% v/v) of ERC biochar could be recommended for chrysanthemum, but that less than 25% v/v may be necessary for ornamental kale.

Open Access

Pesticide application is used in horticulture to reduce plant damage from organisms such as insects and mites. Systemic insecticides are highly efficacious and readily taken up by plant tissues. However, pesticide-treated plants may impose risks to nontarget insects or other organisms within ecosystems. In this study, insecticide residues in nectar, leaves, and flower petals of the horticulturally significant herbaceous annual snapdragon, Antirrhinum majus (Lamiales: Plantaginaceae), were assessed at two locations over several weeks following foliar and drench treatment with five systemic insecticides. Concentrations of the insecticides were determined by liquid chromatography–mass spectrometry. The independent effects Application Method, Application Rate, and Time were statistically significant among all active ingredients in the three matrices in both sites in California (CA) and New Jersey (NJ). The interaction effects were also generally statistically significant in the CA site but less consistently so in the NJ site, dependent on the active ingredient and matrix. Post hoc analyses found the highest residue concentrations in leaves and the lowest in nectar, a trend generally consistent over time regardless of active ingredient for both the CA and NJ sites. The results of this study are discussed in the context of conserving pollinators and other beneficial insects. It is recommended that similar studies should be implemented in different geographical regions and climates, along with multiyear studies for perennial ornamental plants.

Open Access

Many species of herbaceous perennials now have numerous cultivars, with growth habits and flower colors unique to each cultivar. Vegetative propagation is required so that resulting plants are genetically identical to the parent plant. Although many cultivars are selected for precocious and vigorous flowering, it is often difficult to collect adequate vegetative cuttings from such cultivars for commercial production because juvenile (vegetative) growth is preferred for high-quality cuttings. Cuttings that are reproductive (with flower buds or flowers) can have reduced or delayed rooting and increased occurrences of fungal pathogens (especially Botrytis species), resulting in lack of crop uniformity. We sought to answer the question, can growing stock plants of herbaceous perennials under defined photoperiods extend the length of the vegetative period and enhance the rooting of cuttings harvested from these stock plants? In this study, stock plants of ‘P009S’ twinspur (Diascia integerrima), ‘Furman's Red’ sage (Salvia greggii), and ‘Wild Thing’ sage (Salvia greggii) were grown under ambient, 12-hour light, 10-hour light, and 8-hour light to determine if a particular photoperiod could be used to suppress reproductive growth by promoting vegetative growth, thereby enhancing cutting rooting success. Effects of photoperiod treatments varied among the plant cultivars studied. Plants grown under 8-hour photoperiod had longer duration of vegetative growth, smaller growth rates, and lower dry weights when compared with plants grown under 12-hour or 10-hour photoperiod. Plants grown under 12-hour photoperiod had shorter duration of vegetative growth, larger growth rates, and higher dry weights when compared with plants grown under 10-hour and 8-hour photoperiods. The probability of rooting of cuttings harvested from stock plants of ‘P009S’ twinspur, ‘Furman’s Red’ sage, and ‘Wild Thing’ sage grown under 12-hour and 10-hour photoperiods was greater when compared with cuttings harvested from stock plants grown under 8 h photoperiod.

Open Access

During this study, an indoor experiment was conducted to determine the effect of mixed seeding rates of legumes used as green manure on the substrate fertilizer, growth characteristics, and bioactive compounds of baby leaf vegetables. The mixed seeding treatment was designed for milkvetch (Astragalus sinicus L.), tatsoi (Barassica rapa L.), kale (Brassica oleracea var. sabellica L.), and spinach (Spinacia oleracea L.) using five rates for each. Accordingly, a total of 15 treatments (3 baby leaf species × 5 mixed seeding rates) were constructed using a randomized complete block design with three replications for each treatment. During the baby leaf vegetable harvest, we evaluated the macronutrient levels (nitrogen, phosphorus, and potassium) in the substrate as well as the growth parameters and carotenoid contents. The substrate in the treatment mixed with milkvetch showed significantly higher levels of nitrogen, phosphorus, and potassium compared with those of tatsoi and kale sown alone (P ≤ 0.05). However, there were no significant differences in macronutrients observed in substrate-sown spinach with or without the milkvetch mixture. The growth and carotenoid levels of each baby leafy vegetable sown alone were significantly higher than those of each baby leafy vegetable sown with the mixed seeding treatment (P ≤ 0.05). Sowing the milkvetch–vegetable mixtures did not result in a significant increase in the growth and carotenoid levels of the three baby vegetables. The results showed that planting milkvetch with tatsoi and kale had a significant impact on substrate fertilization. However, regarding short-term vertical indoor farming, the growth and carotenoid responses of the three greens may be different. Nonetheless, we still believe that the combined interactions of legumes can provide long-term benefits by enhancing the biological functionality of the growing medium for balanced indoor agriculture production.

Open Access
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When natural days are short, photoperiodic lighting at the end or beginning of the day (day extension) or in the middle of the night (night break) promotes flowering of long-day plants. The objective of this study was to compare broad-spectrum warm-white light-emitting diodes (LEDs) and red (R) + far-red (FR) LEDs at flowering regulation when delivered at different timings in the night period. We performed a greenhouse experiment on four long-day ornamentals [coreopsis (Coreopsis grandiflora) ‘Early Sunrise’, snapdragon (Antirrhinum majus) ‘Liberty Classic Yellow’, petunia (Petunia ×hybrida) ‘Easy Wave Burgundy Star’, and petunia ‘Wave Purple Improved’]. We grew plants under a truncated 8-hour photoperiod with or without low-intensity (∼2 μmol·m−2·s−1) nighttime lighting from warm-white or R+FR LEDs. For each light quality, we delivered four timings: 1) 8 hours after dusk; 2) 8 hours before dawn; 3) 4 hours after dusk + 4 hours before dawn; and 4) 4-hour night break. The effectiveness of floral promotion was determined by time from the treatment onset to the first open flower. Coreopsis flowered similarly under all lighting treatments, irrespective of light quality and timing, but did not flower under the short-day treatment by the end of the experiment. At flowering, coreopsis was 18% to 19% shorter under white than R+FR LEDs. In contrast, snapdragon flowered 9 to 20 days later under white than R+FR LEDs, when delivered for 8 hours at night, but flowered similarly under these two lamp types as a 4-hour night break. Compared with the short-day treatment, white and R+FR LEDs promoted flowering of both petunia cultivars, although flowering generally occurred later under white than R+FR LEDs. Snapdragon and petunia ‘Easy Wave Burgundy Star’ developed 30% to 122% more lateral branches under white than R+FR LEDs, when delivered for 8 hours at night. The effectiveness of warm-white LEDs was generally unaffected by timing, although it was most promotive of flowering in snapdragon when delivered for 8 hours before dawn. For R+FR LEDs, 8-hour day-extension lighting was generally more effective than 4-hour night-break lighting, irrespective of timing. We conclude when delivered for 8 hours at night, warm-white LEDs are generally less effective than R+FR LEDs at promoting flowering of long-day ornamentals but similarly effective as 4-hour night-break lighting. The effectiveness of day-extension lighting is generally independent of timing, although for R+FR LEDs, 8 hours after-dusk and/or before-dawn lighting was generally more effective than 4-hour night-break lighting.

Open Access

This study investigated the activity of upper- and lower-extremity muscles for 15 agricultural tasks of agro-healing. For the development of an agro-healing program using farm resource types, 15 selected agro-healing activities (namely, digging, raking, fertilizing, planting transplants, tying plants to stakes, watering, harvesting, washing, cutting, cooking, collecting natural objects, decorating natural objects, interacting with dogs, walking dogs, and feeding fish) were extracted and performed in a total of 21 adults (average age: 42.29 ± 14.76 years) at D Care Farm in Cheongju, Korea, from June to July 2022. Before these activities, informed consent was obtained from participants and muscle activity of the upper and lower extremities was measured. Muscle activation during activity performance was measured using electromyography (EMG), and the rating of perceived exertion for each activity was investigated. Bipolar surface EMG electrodes were attached at 16 locations on the left and right upper-extremity muscles (anterior deltoid, biceps brachialis, brachioradialis, and flexor carpi ulnaris) and lower-extremity muscles (vastus lateralis, vastus medialis, biceps femoris, and gastrocnemius). The results indicated that the activity of the lower-extremity muscles was higher than that of the upper-extremity muscles during 15 agricultural activities. During plant-mediated activity and animal-assisted activities, the rate of right muscle use was higher than that of left muscle use among the upper-extremity muscles, whereas the rate of right and left muscle use showed a similar tendency among the lower-extremity muscles. During plant-mediated activities, agricultural activities involving the use of heavy tools highly activated the right forearm muscle (flexor carpi ulnaris), whereas holding and interacting with animals highly activated the left forearm muscles (biceps brachialis, brachioradialis, and flexor carpi ulnaris). It is expected that the EMG data obtained in this study can be used as basic biomechanical data when designing an agro-healing program to improve physical function.

Open Access

Bacterial wilt of cucurbits, caused by Erwinia tracheiphila, is spread by spotted (Diabrotica undeimpunctata howardi) and striped (Acalymma vittatum) cucumber beetles and results in major losses for US cucurbit (Cucurbitaceae spp.) growers. Organic growers of muskmelon (Cucumis melo) lack reliable control measures against bacterial wilt. During previous field trials in Iowa, USA, a system called mesotunnels, which are 3.5-ft-tall barriers covered with a nylon mesh insect netting, resulted in a higher marketable yield of organic ‘Athena’ muskmelon than low tunnels or noncovered plots. However, satisfactory pollination and weed control are challenging in mesotunnels because the netting covers the crop for most or all of the growing season, and economic feasibility of these systems has not been determined. Consequently, two field trials conducted in Iowa from 2020 to 2022 evaluated strategies to ensure pollination under mesotunnels in commercial-scale plots, assess effectiveness of teff (Eragrostis tef) as a living mulch for weed control in mesotunnel systems, and compare the profitability of the treatment options for organic ‘Athena’ muskmelon. The treatments used during the pollination trial were as follows: full season, in which mesotunnels remained sealed all season and bumble bees (Bombus impatiens) were added at the start of bloom for pollination; open ends, wherein both ends of the tunnels were opened at the start of bloom then reclosed 2 weeks later; and on-off-on, in which nets were removed at the start of bloom and then reinstalled 2 weeks later. The full-season treatment had significantly higher marketable yield than the other treatments in two of three trial years. Plants with the full season and open ends treatments had a bacterial wilt incidence <2.5% across all three years and similar numbers of cucumber beetles, whereas plants with the on-off-on treatment had an average bacterial wilt incidence of 11.0% and significantly more cucumber beetles. The open ends treatment had fewer bee visits to ‘Athena’ muskmelon flowers than the other treatments. In the 2-year (2021–22) weed management trial, treatments applied to the furrow between plastic-mulched rows were as follows: landscape fabric; teff seeded at 4 lb/acre and mowed 3 weeks after seeding; teff seeded at 4 lb/acre and not mowed; a control with bare ground where weeds were mowed 3 weeks after transplanting; and a bare ground control with no mowing. The landscape fabric and mowed teff treatments had statistically similar marketable yield, and mowing appeared to minimize yield losses compared with nonmowed treatments. The landscape fabric had no weeds, followed by mowed teff, mowed bare ground, and nonmowed teff. Nonmowed bare ground had the highest weed biomass. The partial budget and cost-efficiency ratio analysis indicated that the full-season treatment was the most cost-efficient pollination option for mesotunnel systems. An economic analysis of the weed management strategies showed that using teff as a living mulch in the furrows between organic ‘Athena’ muskmelon rows, coupled with timely mowing to suppress its growth, can generate revenue comparable to that of landscape fabric. Our findings suggest that organic ‘Athena’ muskmelon growers in Iowa may gain the greatest yield and soil quality benefits when mesotunnels are kept closed for the entire season, bumble bees are used for pollination, and teff (mowed 3 weeks after seeding) is used to control weeds in the furrows. Further trials integrating these pollination and weed management strategies would help validate a comprehensive approach to organic ‘Athena’ muskmelon production under mesotunnels.

Open Access

We evaluated several horticultural cultivars and species of Monarda, a genus native to North America with a center of diversity in the Southeast and advertised as beneficial to wildlife, to assess landscape performance with respect to vegetative habit, flower production, and disease tolerance in Georgia Piedmont and montane habitats. We established two experimental sites: the State Botanical Garden of Georgia in Athens (USDA Zone 8b) and the Georgia Mountain Education and Research Center in Blairsville (USDA Zone 7b). We then tracked plant performance over 2 years after establishment. Our study included 10 samples of Monarda, representing five cultivars and four species. Estimated height and width at flowering showed M. bradburiana, M. Sugar Buzz® Grape Gumball, and the M. punctata ecotypes were smaller than other tested taxa. M. fistulosa had the most flowers at the Blairsville site and equal flowering with M. punctata at the Athens location, but most taxa flowered for 2 to 3 months with ∼100 flowering stems per stand. All samples were susceptible to powdery mildew, but M. bradburiana displayed the highest level of tolerance. Otherwise, cultivars tended to be more tolerant to powdery mildew than species. The observed variations in horticultural characteristics and performance highlight the high value of this genus for Georgia landscapes.

Open Access